Refrigeration apparatus



Aug. 14, G p MARCY REFRIGERATION APPARATUS Filed Feb. "23, 1943 WITNESSES: lNVENTOR iii/emo f? MA/cy ATTOR Y Patented Aug. 14, 1945 REFRIGERATION APPARATUS Gerald P. Ma'cy, Longmeadow, Mass., assignoto Westlnghouse Electric Corporation, East Pitt:- burgl, Pa., a corporatlon ot Pennsylvania Application February 23, 1943, Serial No. 476.832

8 claims.

My invention relates to refrigeration apparatus and more particularly to means for automatically and periodically defrosting the cooling unit of such apparatus.

The accumulation of ice or frost on the cooling unit of a refrigerator is due to condensation and ireezing of air-borne moisture on the eflfec tive surtaces of the unit. While some of this moisture is derived from foods stored in the refrigerator, a considerable portion of the moisture is condensed from moist, warm room air which is drawn into the refrigerator every time the door is opened. For practical purposes, it may be stated that the accumulation' of ice on the cooling unit is closely, if not directly, related to the frequency with which the door of the refrigerator is opened during any given period.

It is, therefore, an object of my invention to produce an improved cooling unit defrosting mechanism responsive to the opening and closing of the door of a refrigerator for periodically arresting the operation of the refrigerating machinery which cools said unit, which mechanism is also responsive to the temperature of the unit to cause said refrigerating machnery to resume operation when the temperature of the unit has reached a predetermined upper limit.

Another object of my invention is to produce a defrosting mechanism of the type set forth which in the process of manufacture can be readily and accurately calibrated for satisfactory operation in different locations having different prevailing conditions of temperature and humidity.

Another object of my invention is to produce a reliable and inexpensive defrosting mechanism of the type set forth. Another object of my invention is to produce an improved defrosting mechanism which is compact and flexible and which can be incorporated in any type of mechanical refrigerator without any interference with the normal structure or operation of such refrigerator A further object of the invention is to provide a hydraulic mechanism for initiating defrosting in response to opening and closing of the retrigerator cabinet door and, furthermore, to provide such a defrosting mechanism wherein the switch which is actuated for defrosting may be disposed at any convenient location in the reirigerator cabinet. remote from the door if desired.

A still further object of this invention is to produce an automatic defrosting mechanism which may be in the nature of an auxiliary device Operating independently of the standard temperature control of a refrigerator, or which may be connected directly to the standard control unit as desired.

These and other objects are eflected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part o! this invention, in which:

Fig. 1 is a vertical sectional view of a retrigerator provided with a defrosting means embodying my invention; and, i

Fig. 2 is an enlarged schematic view of the defrosting means.

Referring now to the drawing in detail, l2 designates a conventional retrigerator provided with a food compartment !4 which is cooled by a heatexchange unit IS. s designates a machinery compartment which, in this case, is shown at the bottom of the cabinet. The food compartment H is provided with an access opening s which is closed by a door 20. The machinery in the compartment Is includes a motor-compressor 2| energized by the conductors 22, a tan 23, and a condenser 24 connected by suitable means (not shown) to the evaporator or cooling unit IS. The operation of the motor-compressor 2l is controlled by a conventional temperature control 25 to which temperature variations in the unit li are transmitted by a conventional tube 25 and bulb 21. The parts thus far described may be of any conventional well-known type and hence are not shown nor described in detail, it being sufllcient to state that when the temperature in the unit IS has reached a predetermined upper limit to which the apparatus is adjusted, the reirigerating machinery in the compartment s is energized, and that, when the temperature in the unit IS has reached a lower predetermined limit, the refrigerating machinery is deenergized so as to maintain a predetermined average temperature in the food compartment H.

In order to` deenergize the machinery automatically, periodically, and independently of the temperature of the unit IS, I provide a novel defrosting mechanism which includes a bellows 28 which is provided with a pin or plunger 30. In the present instance, the bellows 28 is shown concealed in the bottom of the food compartment ll but it is to be understood that it may be positioned at any other desired point, as in the top 3| of the compartment l4 or in either of the vertical side jambs of the door opening, it merely being necessary that the pin 30 be so disposed as to project beyond the plane of the door opening so as to be actuated inwardly when the door 20 is closed. The bellows 28 is connected, as by means ot a tube "fto a remotelyplced bellows II which is also provided with a pin or plunger ll. The bellows 2'. tube :I and bellows I! contaln a suitable pressure-transnitting fluid, and the bellows u is preierably biased into contracting position by a spring u. The spring 3! can be dispensed with and the pressure ot the fluid in the system may be regulated to operate the bellows u and s.

The pin Il is pivoted at ll to an arm I! which is pivoted at II to a ratchet wheel u. The arm u can-les a pawl ll which is adapted successively to ensage the teeth of the ratchet wheel u. The am 42 is preterabiy constantly retracted (to the leit in Flg. 2) by the spring I., or a separate spring not shown. A retalning dog ll is suitably pivoted to a support o and tensioned by a spring ll into constant engagement with the ratchet wheel u. The ratchet wheel u also rlgidly carries an arm I! which is adapted to actuate a snapacting device Il with every complete revolution ot the ratchet wheel u. The snap-acting device II carries an arm !I which carries a contactor II. A bulb is posltioned in or near the unit II and is connected to a bellows I! by a tube u. The bulb Il, tube N, and bellows 62 contain an expansible fluid. The bellows I! is provided with an arm u which is pivoted at 'l to an arm ll The arm .25 is pivoted at i! to a suitably fixed support 10. A stop 12 limits the movement of the snap-acting device il. All the parts shown in Flg. 2, except the bellows !I and part of the tube SI, are preferably housed in a box ll and. due to the use o! the hydraulic power transmission mechanism, the box 'M can be placed at any available point close to or remote from the bellows II.

operation The snap-acting device N may be o! any desired conventional construction. As shown, it includes a pivoted arm I! adapted to be engaged or tripped by the arm 52, and a spring H which connects the arm I! to a pivoted arm il which is connected to or carries the arm 56. The arrangenent is such that when the arm 52 depresses the adjacent end oi' the arm 55, the opposite end of the arm u is raised above the pivot point oi' the arm u. This causes the spring 51 to pull on the arms si and u along a line above the pivot point of the arm I! thus raising the arm II and separating the contactor lil from the terminals of the wires 22.

When the retrigerator door is opened, the bel lows !I contracts and the bellows !l expands and moves the pin 30 outwardly or to the left in Fig. l. in which position the pin Il is ready to be actuated when the door is closed. The contraction of the bellows 30 and the expansion of the bellows !I may be the resultant of the spring structure of these bellows and the properly balanced fluid pres'sure in said bellows and in the interconnecting tube u, or, as shown, it is brought about by contraction of the bellows :I under the action of the spring 39. The contraction of the bellow 38 also retracts the pawl I& out of engagement with one tooth of the ratchet and into a position to engage the next succeeding tooth. When the door !I is closed, the pin 30 is moved inwardly to compress the bellows 21. This expands the bellows I! and moves the pin 40 and arm 42, against the i'orce of the spring 39 (to the right in Fig. 2), to rotate the ratchet wheel u through one notch. The dog ll serves to prevent counterclockwise rotation of the ratchet wheel 44 during ascunsa retractlon oi the pswl u. As shown in Pic. 2, the arm u is about to engage and trip the snap-acting device II. It will, however, be understood that after the arm I: has tripped and moved past the adiacent end of the arm Il, the door II may be opened and closed a number ot times equal to the number of teeth on the ratchet wheel u, to cause the ratchet wheel N to make one complete revolution, and to cause the arm I! to engage and actuate the snap-acting device u to raise the arm II and thus separate the contactor I. !rom the terminals of the wires '22. which are connected in series with the standard temperature control 25. This deenergizes the reirigerating apparatus in the compartment ll, and the temperature of the unit i! graduallr rises until the ice or !rost accumulated thereon melts and drops into the drip pan ll. The rise in temperature o! the unit II causes the liquid in the bulb I! to vaporize, thus expanding the bellows 82. This raises the arm II and tilts the !ree end o! the lever I& downwardly against the upper end of the arm !i to return it into the position shown in Fig. 2. In this position, the circuit is completed through the conductors !I to energize the reirigerating apparatus in the compartment I.. The reirigerator now operates subject to the action of its own conventional temperature control 25 until the door 2! has again been opened and closed a number o! timesvequal to the number o! teeth in the ratchet u when the refrosting cycle is again repeated.

It will be seen from the foregoing that I have produced a flexible defrosting mechanism in the sense that it lends itself to easy installation in a number of different ways and in a number oi different locations in a refrigerator cabinet. This renders the construction easily adaptable to different makes of refrigerator oi present as well as oi' future design. This advantage flows directly from the use of the bellows za, connection 38, and bellows s as the hydraulic power-transmitting means, whereby the bellows :I and the remaining structure enclosed in the box 14 can be located at any desired point in the cabinet structure, while the bellows !I and pin III can also be placed at any desired point in the cabinet structure, while the bellows 20 and pin 30 can also be placed at any desired point at which the pin 30 will be actuated every time the door 20 is opened and closed. Since the rate of accumulation o! ice on the cooling unit li is airected by the prevailing humidity, it becomes necessary to adapt the detrosting mechanism for use in diflerent climates. By my construction, this can be readily accomplished by increasing or decreasing the number of teeth on the ratchet wheel u as may be dictated by the varying requirements of localities having different degrees of relative humidity.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible ol' various changes and modifications without departing from the spirit thereof. and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set fcrth in the appended claims.

What I claim is:

1. The combination with a refrigerator including a food compartment having an access opening thereto, a door for closing said opening, a hoat-exchange unit for cooling said Compartment, and a refrigerating apparatus ior maintaining said unit at a below-Ireezing temperature,

of hydraulc means responsive to the opening and closing of said door for rendering said refrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times, and means for again rendering said refrigerating apparatus operative.

2. The combination with a. refrigerator including a food compartment having an access opening, a door for closing said opening, a beat-exchange unit for cooling said compartment, and a refrigerating apparatus for maintaining said unit at a below-freezing temperature, of hydraulic means responsive to the opening and closing of said door, and control means actuated by said hydraulic meanseach time said door is opened and closed, said control means being effective to render said refrigerating apparatus inoperative when said door has been opened and closed apredetermined number of times. i 3. The combination with a refrigerator including a food com-partment having an access opening, a door for closing said opening, a beat-exchange unit for cooling said compartment, and a retrigerating apparatus for maintaining said unit at a below-freezing temperature, of hydraulic means responsive to the opening and closing of said door, control means actuated by said hydraulic means each time said door is opened and closed, said control means being efiective to render said refrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times, and means responsive to the rise in temperature of said unit for again rendering said refrigerating apparatus operative.

4. The combination with a refrigerator including a food compartment having an access openins. a door for closing said opening, a heatexchange unit for cooling said compartment, and a retrigerating apparatus for maintaining said unit at a below-freezing temperature, of dooractuated means responsive to the opening and closing of said door, remotely disposed defrosting control means, and hydraulic actual-.ing means operatively connected :to said door-actuated means and said defrosting control means for actuating said defrosting control means to render said defrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times.

5. The oombination with a refrigerator including a food compartment having an access opening, a door for closing said opening, a heatexchange unit for cooling said compartment, and a' retrigerating apparatus tor maintaining said. unit at a below-freezing temperature, of dooraotuated means responsive to the opening and closing ot said door. remotely disposed den-osting control means, hydraulic actuating means operatively connected :to said door-actuated means and said defrosting control means for actuating said retrosting control means to rendor said refrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times, and means responsive to increased temperature in said unit for again rendaring said retrigerwting apparatus operative.

6. The combination with a retrigerator including a food compartment havinl n access opening thereto, a door for closing said opening, a beat-exchange unit for cooling said compartmcnt, and a reirigerating apparatus for maintaining said unit at a below-freezing temperature of hydraulic means adapted to be actuated by the opening and closing of said door, a hydraulic power-transmitting .tube having one end thereof operatively connected .to said hydraulic means, a second hydraulic means connected to .the other end of said .tube and operable in response to the operation of said first hydraulic means, and means actuated by said second hydraulic means for rendering said refrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times.

7. The combination with a refrigerator including a food compartment having an access opening thereto, a door for closing said opening, a beat-exchange unit for cooling said compantment, and a refrigerating apparatus for maintaning said unit at a below-freezing temperature, of hydraulic means adapted to be actuated by .the opening and closing of said door, a hydraui lic power-transmitting' tube having one end thereof operatively connected to said hydraulic means, a second hydraulic means connected to the other end of said tube and operable in response to the operation of said first` hydraulic means, means actuated by said second hydraulic means for rendering said refrigerating apparatus inoperative when said door has been opened and closed a predetermined number of times, and means responsive to rise in temperature of said unit for again rendering said refrigerating apparatus operative.

8. The combination with arefrigerator including a, food compartment having an access opening therefor, a door for closing said opening, a hoat-exchange unit for cooling said compartment,

,and a refrigerating apparatus for maintaining' said unit at a below-freezing temperature, of means responsive to the number of times said door is opened and closed for rendering said refrigerating apparatus inoperative comprising a bellows, a projection connected to said bellows. said projection and said bellows being soconstructed and arranged that when said door is open said projection moves beyond the plane of said door !rame by expansion o! said bellows, and when said door is closed, said projection moves in the opposite direction to compress said bellows, a hydraulic power-transmitting element connected at one end to the interior of said bellows, a second bellows interiorly connected to the other end of said power-transmitting element, a pressure-transmitting fluid in said element and said bellows, a ratchet wheel having a predetermined number ot teeth, a pawl engaging said ratchet wheel and operatively connected (to and actuated by expansion and contraction of said second bellows to turn said ratchet wheel through a predetermined distance with every opening and GERALD P. minds. 

